GE L90 Instruction Manual page 465

CHAPTER 5: SETTINGS
For ground distance zone 2, there is a provision to start the zone timer with the other distance zones or loop pickup
flags to avoid prolonging ground distance zone 2 operation if the fault evolves from one type to another or
migrates from zone 3 or 4 to zone 2. Assign the required zones in the trip output element to accomplish this
functionality.
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
Figure 5-126: Ground distance zone 1 OP scheme
Figure 5-127: Ground distance zone 2 OP scheme
GROUPED ELEMENTS
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